Hello Everyone,
This is a review and detailed measurements of the Yamaha C-2 preamplifier.
Yamaha C-2 - Presentation
The Yamaha C-2 is a vintage preamplifier that was available from 1976 to 1978. It was the little brother of the crazy expensive C-1 which I encourage you to lookup on the web.
Anyways, this more modest C-2 was not cheap as it would reach $3'000 is today's money! Despite the slim look, this is a relatively heavy one, at near 7.8kg (17.2lbs)
As you can see from the front face, it offers the essential:
From the above, we can suspect a good performer, from 50 years ago!
And, as I'd love to see every time, Yamaha also published the below measurements:
It will be my pleasure to go check if I find the same!
On the front panel, the words “Natural Sound” are printed, and I guess it is an elegant way of saying “transparent.” Based on the specifications and the limited measurements we get, this holds true. Notably, Yamaha still uses the “Natural Sound” branding on its current products.
Let's have a quick look at the back:
Yeah, we have 3 phono inputs... and two pre-out, and possibility to connect two tape deck.
User experience
Not much to say, honestly, except that it is easy to use. The balance is a ring around the volume knob, not practical if you ask me.
The finish of this Yamaha is quite good, and the thick aluminum front and top panels provide the happy owner with a luxury touch. As opposed to the Accuphase preamps I previously reviewed, the volume knob does not have that silky touch, but it is more than ok. All buttons are aluminum made, and that again says a lot about the quality.
And sorry, no pictures of the inside, I simply did not find the time. I'll correct that in the future but they are easy to find on the web.
Yamaha C-2 - Measurements (Line)
All measurements performed with an E1DA Cosmos ADCiso (grade 0), and the Cosmos Scaler (100kohms from unbalanced input). I used a SMSL PS200 as the generator of the test tones.
I previously reviewed the Accuphase C-200X, released couple of years later. I encourage you to compare the measurements since I kept them aligned for that purpose.
The channel imbalance of the Yamaha is a small 0.1dB and the phase is almost flat (+-8°).
Let's start with the standard 1kHz at max gain (roughly 15.3dB), from a 0.5Vrms input, meaning 2.9Vrms output:
This is much less gain than the Accuphase C-200X, but we get a SINAD of 104.5dB, and that is more than 17bits of resolution. The distortion is very low and so the limit is only the low level noise. I was honestly not expecting that good.
Let's try the same at unity gain, with 2.2Vrms input/output:
Wow, this time it's even better than the Accuphase. I am impressed. That typically means that the CD Audio signal is preserved, well done for a device that was born way before the CDA.
----
Note that there is a small PS leakage as we can see on the zoomed view below:
You can see a spike at 50Hz (Europe), but @-120dBr, it will remain hidden into music.
----
Let's continue with the famous Multitone, from the AudioPrecision file that Amir shared a while ago:
The Yamaha has less distortion than the Accuphase C-200X so I had to increase the scale to go down to -140dB. Besides few spikes, we see more than 20bits of distortion-free range!
----
Next, bandwidth and phase:
This is very flat, no suprises.
----
The below is a measurement of THD+N ratio vs frequency, with an extended bandwidth to capture all distortion and noise components up to 90kHz:
The trace is nearly the same as with the Accuphase C-200X, and no increase of distortion at high frequencies. Seeing that type of performance from a 50 years old device, well... no comments.
----
Let's move on to intermodulation test, with the IDM SMPTE (60Hz & 7kHz 4:1) sweep vs input level:
Again, the Yamaha beats the Accuphase C-200X, and gets very close to the C-280. Nice.
----
Other measurements (not shown):
----
Oh, and I will add a view of the tones influence at maximum:
There's no "Defeat" button for the tones, and the green line is when set at 0. The others are at -10/+10. This is nicely done.
----
Last, and since Yamaha showed it in their measurements, this is a view of the subsonic filter:
It's the same as documented.
----
With all the above, I state that the line stage of this preamplifier offered staggering performances in 1976. And so, that is the "Natural Sound" of Yamaha. I'm ok with that!
Yamaha C-2 - Measurement (Phono MM)
This is a thoughtfully designed line‑stage amplifier, and as usual, I’m particularly looking forward to the phono stage, where vintage equipment has always shone.
Let's start with the standard SINAD, with an input of 40mVrms and 40dB gain:
This is the signal as it comes out from the Phono preamp, meaning I did not compensated the RIAA curve. The results are very good, nearly identical to that of the Accuphase C-200X, I am again impressed.
Now, let's correct the RIAA curve, with the software, to simulate how a record would be created, with the opposite curve:
With that view, the Yamaha C-2 does even better than the amazing Accuphase C-280.
Note: I use a 40mVrms input for that test because some dynamic cartridges (eg: Shure M44-7 - 9mVrms for 5cm/sec), together with over-cut records, would be reaching a speed velocity of 30cm/sec, meaning they'd reach or go beyond 60mVrms. And to add to that, I'm using a 40dB gain amplification, as this is very common, and so with 40mVrms at the input, we get 4Vrms at the output, for the above test.
----
Next set of measurements for a phono preamp is related to the above. It is important to know at what point it will clip, depending on the frequency. We need a good headroom, and all vintage phono preamps were known to excel on that perspective.
This is measured with a sweep of THD vs input level, at different frequencies:
As opposed to the measurements of Yamaha, the first sine I used is 100Hz instead of 20Hz, this is to align with my other reviews.
One more time, the headroom we get from this phono stage is nothing else than crazy, although a little less that with the previously mentioned Accuphase. That said, 300mVrms at 1kHz before clipping, wow...
Please appreciate also the very low level of distortion on these tets. No record player needs that good.
----
Ok, bandwidth, as we need to check the respect of the RIAA curve:
A +0.1 dB bump at 50 Hz is hardly enough to make the sound warm, yet one has to wonder whether Yamaha did this deliberately. Considering the rest of the stellar performance (in 1976), I think it is plausible.
----
Oh, yes, for the fun, as @amirm likes the below measurement. It is a sweep of THD only (no noise) with an extended bandwidth up to 90kHz to capture distortion at high frequencies too:
The left channel exhibits more distortion below 1 kHz, though it’s easily hidden with a turntable as the source. At 1 kHz, the Yamaha once again narrowly outperforms the Accuphase C‑200X by a hair.
Conclusion
Very low distortion, low noise, high headroom, and a flat frequency response, this is what Yamaha refers to as “Natural Sound.”
It is always a great pleasure to test these vintage devices, especially when they perform at such a high level. The C‑2 outperformed every source available at the time, which is arguably the best definition of transparency. So much so, in fact, that even the Compact Disc pairs effortlessly with this preamp.
Yamaha has long been one of my favorite brands, and testing this unit has only strengthened that appreciation. i wish I still had my C-6 to run the same tests!
I hope you enjoyed this review and I wish you a lovely weekend.
Flo
This is a review and detailed measurements of the Yamaha C-2 preamplifier.
Yamaha C-2 - Presentation
The Yamaha C-2 is a vintage preamplifier that was available from 1976 to 1978. It was the little brother of the crazy expensive C-1 which I encourage you to lookup on the web.
Anyways, this more modest C-2 was not cheap as it would reach $3'000 is today's money! Despite the slim look, this is a relatively heavy one, at near 7.8kg (17.2lbs)
As you can see from the front face, it offers the essential:
- MM and MC phono inputs
- Tone controls (no defeat button)
- A subsonic filter (too often forgotten in modern preamps)
- A mute button that reduces the output gain by 20dB
- Several modes of operation (mono, stereo, inverted polarity)
From the above, we can suspect a good performer, from 50 years ago!
And, as I'd love to see every time, Yamaha also published the below measurements:
It will be my pleasure to go check if I find the same!
On the front panel, the words “Natural Sound” are printed, and I guess it is an elegant way of saying “transparent.” Based on the specifications and the limited measurements we get, this holds true. Notably, Yamaha still uses the “Natural Sound” branding on its current products.
Let's have a quick look at the back:
Yeah, we have 3 phono inputs... and two pre-out, and possibility to connect two tape deck.
User experience
Not much to say, honestly, except that it is easy to use. The balance is a ring around the volume knob, not practical if you ask me.
The finish of this Yamaha is quite good, and the thick aluminum front and top panels provide the happy owner with a luxury touch. As opposed to the Accuphase preamps I previously reviewed, the volume knob does not have that silky touch, but it is more than ok. All buttons are aluminum made, and that again says a lot about the quality.
And sorry, no pictures of the inside, I simply did not find the time. I'll correct that in the future but they are easy to find on the web.
Yamaha C-2 - Measurements (Line)
All measurements performed with an E1DA Cosmos ADCiso (grade 0), and the Cosmos Scaler (100kohms from unbalanced input). I used a SMSL PS200 as the generator of the test tones.
I previously reviewed the Accuphase C-200X, released couple of years later. I encourage you to compare the measurements since I kept them aligned for that purpose.
The channel imbalance of the Yamaha is a small 0.1dB and the phase is almost flat (+-8°).
Let's start with the standard 1kHz at max gain (roughly 15.3dB), from a 0.5Vrms input, meaning 2.9Vrms output:
This is much less gain than the Accuphase C-200X, but we get a SINAD of 104.5dB, and that is more than 17bits of resolution. The distortion is very low and so the limit is only the low level noise. I was honestly not expecting that good.
Let's try the same at unity gain, with 2.2Vrms input/output:
Wow, this time it's even better than the Accuphase. I am impressed. That typically means that the CD Audio signal is preserved, well done for a device that was born way before the CDA.
----
Note that there is a small PS leakage as we can see on the zoomed view below:
You can see a spike at 50Hz (Europe), but @-120dBr, it will remain hidden into music.
----
Let's continue with the famous Multitone, from the AudioPrecision file that Amir shared a while ago:
The Yamaha has less distortion than the Accuphase C-200X so I had to increase the scale to go down to -140dB. Besides few spikes, we see more than 20bits of distortion-free range!
----
Next, bandwidth and phase:
This is very flat, no suprises.
----
The below is a measurement of THD+N ratio vs frequency, with an extended bandwidth to capture all distortion and noise components up to 90kHz:
The trace is nearly the same as with the Accuphase C-200X, and no increase of distortion at high frequencies. Seeing that type of performance from a 50 years old device, well... no comments.
----
Let's move on to intermodulation test, with the IDM SMPTE (60Hz & 7kHz 4:1) sweep vs input level:
Again, the Yamaha beats the Accuphase C-200X, and gets very close to the C-280. Nice.
----
Other measurements (not shown):
- Input voltage clipping: above 4Vrsm (I can't go higher more with unbalanced).
- Output voltage clipping: above 10Vrms (I can't measure more).
- Dynamic Range (CCIR 2k weighted): from 101dB at unity gain to 117dB at max gain.
- IMD AES (18kHz + 20kHz 1:1) : below -119dB from unity gain and above!
----
Oh, and I will add a view of the tones influence at maximum:
There's no "Defeat" button for the tones, and the green line is when set at 0. The others are at -10/+10. This is nicely done.
----
Last, and since Yamaha showed it in their measurements, this is a view of the subsonic filter:
It's the same as documented.
----
With all the above, I state that the line stage of this preamplifier offered staggering performances in 1976. And so, that is the "Natural Sound" of Yamaha. I'm ok with that!
Yamaha C-2 - Measurement (Phono MM)
This is a thoughtfully designed line‑stage amplifier, and as usual, I’m particularly looking forward to the phono stage, where vintage equipment has always shone.
Let's start with the standard SINAD, with an input of 40mVrms and 40dB gain:
This is the signal as it comes out from the Phono preamp, meaning I did not compensated the RIAA curve. The results are very good, nearly identical to that of the Accuphase C-200X, I am again impressed.
Now, let's correct the RIAA curve, with the software, to simulate how a record would be created, with the opposite curve:
With that view, the Yamaha C-2 does even better than the amazing Accuphase C-280.
Note: I use a 40mVrms input for that test because some dynamic cartridges (eg: Shure M44-7 - 9mVrms for 5cm/sec), together with over-cut records, would be reaching a speed velocity of 30cm/sec, meaning they'd reach or go beyond 60mVrms. And to add to that, I'm using a 40dB gain amplification, as this is very common, and so with 40mVrms at the input, we get 4Vrms at the output, for the above test.
----
Next set of measurements for a phono preamp is related to the above. It is important to know at what point it will clip, depending on the frequency. We need a good headroom, and all vintage phono preamps were known to excel on that perspective.
This is measured with a sweep of THD vs input level, at different frequencies:
As opposed to the measurements of Yamaha, the first sine I used is 100Hz instead of 20Hz, this is to align with my other reviews.
One more time, the headroom we get from this phono stage is nothing else than crazy, although a little less that with the previously mentioned Accuphase. That said, 300mVrms at 1kHz before clipping, wow...
Please appreciate also the very low level of distortion on these tets. No record player needs that good.
----
Ok, bandwidth, as we need to check the respect of the RIAA curve:
A +0.1 dB bump at 50 Hz is hardly enough to make the sound warm, yet one has to wonder whether Yamaha did this deliberately. Considering the rest of the stellar performance (in 1976), I think it is plausible.
----
Oh, yes, for the fun, as @amirm likes the below measurement. It is a sweep of THD only (no noise) with an extended bandwidth up to 90kHz to capture distortion at high frequencies too:
The left channel exhibits more distortion below 1 kHz, though it’s easily hidden with a turntable as the source. At 1 kHz, the Yamaha once again narrowly outperforms the Accuphase C‑200X by a hair.
Conclusion
Very low distortion, low noise, high headroom, and a flat frequency response, this is what Yamaha refers to as “Natural Sound.”
It is always a great pleasure to test these vintage devices, especially when they perform at such a high level. The C‑2 outperformed every source available at the time, which is arguably the best definition of transparency. So much so, in fact, that even the Compact Disc pairs effortlessly with this preamp.
Yamaha has long been one of my favorite brands, and testing this unit has only strengthened that appreciation. i wish I still had my C-6 to run the same tests!
I hope you enjoyed this review and I wish you a lovely weekend.
Flo
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